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This paper aims to introduce the concept and objectives of a recently supported European project entitled "Geomatics and Civil Engineering Innovative Research on Heritage", in short ENGINEER. The ENGINEER project visions to enhance and extend inter-departmental multidisciplinary research activities of the Department of Civil Engineering & Geomatics of the Cyprus University of Technology through coordination and support actions as well as through targeted research activities with the support of European leading institutions. Project tasks aim to fill research multidisciplinary gaps, push, and extend knowledge into new and innovative fields dealing with the monitoring, digitization, visualization, and preservation of ancient monuments and cultural heritage sites, assisting their protection, promotion, and safeguarding. [ABSTRACT FROM AUTHOR]

The fusion of geomatic techniques with different accuracy and resolution has been used in recent years to applications of geometrical documentation for several archaeological sites. In this research article, the case of the Roman Baths of Amathus in Limassol, Cyprus was investigated.Aerial photogrammetry and Terrestrial Laser Scanning (TLS) techniques were used to produce the final product. The photogrammetric data were based on Post-Processed Kinematic (PPK) imagery while the TLS georeference was based on targets.The main research objective of this paper is to examine the reliability of PPK photogrammetric data without the use of Ground Control Points (GCPs) and how well they can be integrated with TLS data. Also, the two acquisition techniques were compared and indicated that 0.005 m Ground Sampling Distance (GSD) resolution aerial images and 0.0061/10 m resolution scans can be qualitatively fused.The research paper will present the entire methodology up to the generation of the final 3D photorealistic product. [ABSTRACT FROM AUTHOR]

The dissolution of a dislocation loop layer under the influence of inert Si[O.sub.2]/Si and nitrogen-rich Si[O.sub.2]/Si interfaces is studied. The results have shown that during the nonconservative Ostwald ripening process the defect band loses interstitials mainly due to the dissolution of perfect prismatic loops, while Frank loops remain almost unaffected by the presence of both interfaces.

A new study uses the wafer bonding technique to investigate the interaction between silicon interstitials and dislocation loops during thermal oxidation.

The interstitial injection during nitrous oxidation of silicon at low temperatures was monitored using dislocation loops and boron-doped delta layers.

The problem of colour correction of underwater images concerns not only surveyors, who primarily use images for photogrammetric purposes, but also archaeologists, marine biologists, and many other domains experts whose aim is to study objects and lifeforms underwater. Different methods exist in the literature; some of them provide outstanding results but works involving physical models that take into account additional information and variables (light conditions, depths, camera to objects distances, water properties) that are not always available or can be measured using expensive equipment or calculated using more complicated models. Some other methods have the advantages of working with basically all kinds of dataset, but without considering any geometric information, therefore applying corrections that work only in very generic conditions that most of the time differs from the real-world applications.This paper presents an easy and fast method for restoring the colour information on images captured underwater. The compelling idea is to model light backscattering and absorption variation according to the distance of the surveyed object. This information is always obtainable in photogrammetric datasets, as the model utilises the scene's 3D geometry by creating and using SfM-MVS generated depth maps, which are crucial for implementing the proposed methodology. The results presented visually and quantitatively are promising since they are an excellent compromise to provide a straightforward and easily adaptable workflow to restore the colour information in underwater images. [ABSTRACT FROM AUTHOR]

The aim of this study is to develop a low-cost mobile mapping system (MMS) with the integration of vehicle-based navigation data and stereo images acquired along vehicle paths. The system consists of a dual frequency GNSS board combined with a low-cost INS unit and two machine vision cameras that collect colour image data for road and roadside objects. The navigation data and the image acquisition are properly synchronized to associate position and attitude to each digital frame captured. In this way, upon pixel location of objects appearing on the video frames, their absolute geographical coordinates can be extracted by employing standard photogrammetric methods. Several calibration steps are implemented before survey operation: camera calibration, relative orientation between cameras and determination of rotation angles and offsets between vehicle and cameras reference frames. A software tool has been developed to facilitate and speed up the calibration procedures. Furthermore, easy object coordinate extraction is supported, either in auto mode, where the conjugate image coordinates are obtained in real time using image correlation techniques. Several surveying experiments were executed to certify and check the accuracy and efficiency of the system. From the achieved results, the developed system is efficient for collecting and positioning road spatial objects such as such as road boundaries, traffic lights, road signs, power poles, etc, more rapidly and less expensively. The obtained absolute positional accuracy is less than 1 meter, depending on the availability and quality of the GPS signal. [ABSTRACT FROM AUTHOR]

In this work ultrathin strained silicon layers grown on relaxed Si0.9Ge0.1 substrates were oxidized under high thermal budget conditions in N2O ambient at 800 °C. The results indicate that the density of interface traps depends on the extent of the oxidation process. If the strained Si layer is totally consumed the density of interface traps reduces to almost half the value as compared to the case where a part of the strained Si layer still remains. The results indicate that the two existing interfaces of the strained Si layer, the SiO2/strained-Si and the strained-Si/Si0.9Ge0.1, contribute in parallel to the measured interface trap density. In addition, the buried strained-Si/Si0.9Ge0.1 interface constitutes a major source of the observed high density of interface traps. [ABSTRACT FROM AUTHOR]

In this work we develop a simple macroscopic model for the prediction of arsenic diffusion in silicon under low energy-high dose implantation conditions. Under these conditions, As-enhanced diffusion is attributed mainly to interstitial injection due to the formation of As-vacancy clusters. The basis of the model is the introduction of a bulk interstitial generation source from the entire As distribution, taking into account the difference between the chemical and active profiles of the dopant during drive-in annealing. The model has been introduced to the SYNOPSYS-TAURUS process simulator in order to simulate the results of an experiment especially designed for this purpose. Very satisfactory simulation results have been obtained, taking into account the simplicity of the model. Moreover, the model predicts, at least for short annealing times, the initial stage (trend) of the well-known arsenic uphill diffusion phenomenon at the native oxide/silicon interface. [ABSTRACT FROM AUTHOR]

In this work we perform a systematic study of the dissolution of a dislocation loop layer under the influence of inert SiO2/Si and nitrogen-rich SiO2/Si interfaces. The composition of the dislocation loop layer was just after its formation 10%–20% Frank dislocation loops and 90%–80% perfect prismatic loops. During subsequent inert (N2) ambient annealing the differences of the kinetics between the two loop populations have been studied as a function of the interface type. It has been shown that during the nonconservative Ostwald ripening process the defect band loses interstitials mainly due to the dissolution of perfect prismatic loops, while Frank loops remain almost unaffected by the presence of both interfaces. In parallel a competition between the interface and the population of Frank loops in absorbing the interstitials released by the prismatic loops took place. The nitrogen-rich SiO2/Si interface has been proved in general a less effective interstitial sink than the common one and under specific annealing conditions less effective even than the small Frank loops population. [ABSTRACT FROM AUTHOR]

In this article we study the interstitial injection during oxidation of very low-energy nitrogen-implanted silicon. Buried boron δ layers are used to monitor the interstitial supersaturation during the oxidation of nitrogen-implanted silicon. No difference in boron diffusivity enhancement was observed compared to dry oxidation of nonimplanted samples. This result is different from our experience from N2O oxynitridation study, during which a boron diffusivity enhancement of the order of 20% was observed, revealing the influence of interfacial nitrogen on interstitial kinetics. A possible explanation may be that implanted nitrogen acts as an excess interstitial sink in order to diffuse towards the surface via a non-Fickian mechanism. This work completes a wide study of oxidation of very low-energy nitrogen-implanted silicon related phenomena we performed within the last two years [D. Skarlatos, C. Tsamis, and D. Tsoukalas, J. Appl. Phys. 93, 1832 (2003); D. Skarlatos, E. Kapetanakis, P. Normand, C. Tsamis, M. Perego, S. Ferrari, M. Fanciulli, and D. Tsoukalas, J. Appl. Phys. 96, 300 (2004)]. [ABSTRACT FROM AUTHOR]

In a previous work [Skarlatos et al., J. Appl. Phys. 93, 1832 (2003)] we investigated the influence of implantation energy on oxide growth and defect formation in nitrogen-implanted silicon substrates. It was shown that as the implantation energy decreases from medium to very low values the oxide reduction decreases. This was attributed to nitrogen out-diffusion, which is more effective when nitrogen is placed closer to the silicon surface. On the other hand very low implantation energy avoids the formation of dislocation loops in the silicon substrate, a key point for modern devices performance. In this second part we compare the nitrogen distribution and electrical properties of ultrathin (25–30 Å) oxides grown under the same oxidation conditions on very low (3 keV) and medium (25 keV) energy nitrogen-implantated silicon. Nitrogen distribution measurements show that a lower content of nitrogen remains within the oxides formed using 3 keV energy as compared to the 25 keV case supporting the results of the first part of this work. So at very low implantation energy the same oxide thickness is obtained increasing the implantation dose. On the other hand oxides formed through very low energy implants show superior electrical properties in terms of surface states and leakage currents due to the lower damage induced in the silicon substrate. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

It is well known that nitrogen implantation in silicon leads in reduction of the SiO[sub 2] thickness in implanted wafers, which makes this a very promising technique for present and future device processing. In this work we investigate the influence of the implantation energy on oxidation kinetics in nitrogen-implanted silicon. Nitrogen was implanted in silicon wafers at low (3 keV), and medium (25, 80, and 150 keV) energies and oxidations were performed at various temperatures (800-900 °C) and times. The experiment shows that the decrease in the oxide thickness is smaller when nitrogen is implanted closer to the silicon surface. We attribute this to nitrogen out-diffusion during the ramping and the initial oxidation steps, which is more effective when nitrogen is placed closer to the surface. Additional experiments varying the ramping time support this explanation. An additional study of the growth of extended defects under the different implantation conditions has been performed. This study enabled the estimation of an energy-dose "window," in which we can observe very small oxide thickness (25-40 Å) without extended defects formation. [ABSTRACT FROM AUTHOR]

The interstitial injection during oxidation of very low-energy nitrogen-implanted silicon is studied. A buried boron delta layer is used to monitor the interstitial supersaturation during the oxidation of nitrogen-implanted silicon.

Electrical properties of ultra thin gate oxides formed by oxidation of nitrogen implanted silicon and nitrogen distribution were studied. Absence of extended defects in the silicon substrate and lower interfacial damaged have resulted in better nitrogen distribution in the 3 and 25 KeV implanted samples which were identical.

This paper presents an investigation as to whether and how the selection of the SfM-MVS software affects the 3D reconstruction of submerged archaeological sites. Specifically, Agisoft Photoscan, VisualSFM, SURE, 3D Zephyr and Reality Capture software were used and evaluated according to their performance in 3D reconstruction using specific metrics over the reconstructed underwater scenes. It must be clarified that the scope of this study is not to evaluate specific algorithms or steps that the various software use, but to evaluate the final results and specifically the generated 3D point clouds. To address the above research issues, a dataset from the ancient shipwreck, laying at 45 meters below sea level, is used. The dataset is composed of 19 images having very small camera to object distance (1 meter), and 42 images with higher camera to object distance (3 meters) images. Using a common bundle adjustment for all 61 images, a reference point cloud resulted from the lower dataset is used to compare it with the point clouds of the higher dataset generated using the different photogrammetric packages. Following that, a comparison regarding the number of total points, cloud to cloud distances, surface roughness, surface density and a combined 3D metric was done to evaluate and see which one performed the best. [ABSTRACT FROM AUTHOR]

The determination of accurate bathymetric information is a key element for near offshore activities, hydrological studies such as coastal engineering applications, sedimentary processes, hydrographic surveying as well as archaeological mapping and biological research. UAV imagery processed with Structure from Motion (SfM) and Multi View Stereo (MVS) techniques can provide a low-cost alternative to established shallow seabed mapping techniques offering as well the important visual information. Nevertheless, water refraction poses significant challenges on depth determination. Till now, this problem has been addressed through customized image-based refraction correction algorithms or by modifying the collinearity equation. In this paper, in order to overcome the water refraction errors, we employ machine learning tools that are able to learn the systematic underestimation of the estimated depths. In the proposed approach, based on known depth observations from bathymetric LiDAR surveys, an SVR model was developed able to estimate more accurately the real depths of point clouds derived from SfM-MVS procedures. Experimental results over two test sites along with the performed quantitative validation indicated the high potential of the developed approach. [ABSTRACT FROM AUTHOR]

Underwater archaeological discoveries bring new challenges to the field, but such sites are more difficult to reach and, due to natural influences, they tend to deteriorate fast. Photogrammetry is one of the most powerful tools used for archaeological fieldwork. Photogrammetric techniques are used to document the state of the site in digital form for later analysis, without the risk of damaging any of the artefacts or the site itself. To achieve best possible results with the gathered data, divers should come prepared with the knowledge of measurements and photo capture methods. Archaeologists use this technology to record discovered arteacts or even the whole archaeological sites. Data gathering underwater brings several problems and limitations, so specific steps should be taken to get the best possible results, and divers should well be prepared before starting work at an underwater site. Using immersive virtual reality, we have developed an educational software to introduce maritime archaeology students to photogrammetry techniques. To test the feasibility of the software, a user study was performed and evaluated by experts. In the software, the user is tasked to put markers on the site, measure distances between them, and then take photos of the site, from which the 3D mesh is generated offline. Initial results show that the system is useful for understanding the basics of underwater photogrammetry. [ABSTRACT FROM AUTHOR]

The paper presents the application of some Virtual Reality technologies developed in the Horizon 2020 i-MARECulture project to the case study of the sunken "Villa con ingresso a protiro", dated around the II century AD, and located in the Marine Protected Area - Underwater Park of Baiae (Naples).The i-MARECulture project (www.imareculture.eu), in fact, aims to improve the public awareness about the underwater cultural heritage by developing new tool and techniques that take advantage of the virtual reality technologies to allow the general public to explore the archaeological remains outside of the submerged environment.To this end, the paper details the techniques and methods adopted for the development of an immersive virtual tour that allow users to explore, through a storytelling experience, a virtual replica and a 3D hypothetical reconstruction of the complex of the "Villa con ingresso a protiro". [ABSTRACT FROM AUTHOR]

Given the rise and wide adoption of Structure from Motion (SfM) and Multi View Stereo (MVS) in underwater archaeology, this paper investigates the optimal option for surveying ground control point networks. Such networks are the essential framework for coregistration of photogrammetric 3D models acquired in different epochs, and consecutive archaeological related study and analysis. Above the water, on land, coordinates of ground control points are determined with geodetic methods and are considered often definitive. Other survey works are then derived from by using those coordinates as fixed (being ground control points coordinates considered of much higher precision). For this reason, equipment of proven precision is used with methods that not only compute the most correct values (according to the least squares principle) but also provide numerical measures of their precisions and reliability. Under the water, there are two options for surveying such control networks: trilateration and photogrammetry, with the former being the choice of the majority of archaeological expeditions so far. It has been adopted because of ease of implementation and under the assumption that it is more reliable and precise than photogrammetry.This work aims at investigating the precision of network establishment by both methodologies by comparing them in a typical underwater archaeological site. Photogrammetric data were acquired and analysed, while the trilateration data were simulated under certain assumptions. Direct comparison of standard deviation values of both methodologies reveals a clear advantage of photogrammetry in the vertical (Z) axis and three times better results in horizontal precision. [ABSTRACT FROM AUTHOR]

The main idea of this particular study was to validate if the new FOVEON technology implemented by sigma cameras can provide better overall results and outperform the traditional Bayer pattern sensor cameras regarding the radiometric information that records as well as the photogrammetric point cloud quality that can provide. Based on that, the scope of this paper is separated into two evaluations. First task is to evaluate the quality of information reconstructed during de-mosaicking step for Bayer pattern cameras by detecting potential additional colour distortion added during the de-mosaicking step, and second task is the geometric comparisons of point clouds generated by the photos by Bayer and FOVEON sensors against a reference point cloud. The first phase of the study is done using various de-mosaicking algorithms to process various artificial Bayern pattern images and then compare them with reference FOVEON images. The second phase of the study is carried on by reconstructing 3D point clouds of the same objects captured by a Bayer and a FOVEON sensor respectively and then comparing the various point clouds with a reference one, generated by a structured light hand-held scanner. The comparison is separated into two parts, where initially we evaluate five separate point clouds (RGB, Gray, Red, Green, Blue) for each camera sensor per site and then a second comparison is evaluated on colour classified RGB point cloud segments. [ABSTRACT FROM AUTHOR]

In this paper, main challenges of underwater photogrammetry in shallow waters are described and analysed. The very short camera to object distance in such cases, as well as buoyancy issues, wave effects and turbidity of the waters are challenges to be resolved. Additionally, the major challenge of all, caustics, is addressed by a new approach for caustics removal (Forbes et al., 2018) which is applied in order to investigate its performance in terms of SfM-MVS and 3D reconstruction results. In the proposed approach the complex problem of removing caustics effects is addressed by classifying and then removing them from the images. We propose and test a novel solution based on two small and easily trainable Convolutional Neural Networks (CNNs). Real ground truth for caustics is not easily available. We show how a small set of synthetic data can be used to train the network and later transfer the le arning to real data with robustness to intra-class variation. The proposed solution results in caustic-free images which can be further used for other tasks as may be needed. [ABSTRACT FROM AUTHOR]

Current advancements on photogrammetric software along with affordability and wide spreading of Unmanned Aerial Vehicles (UAV), allow for rapid, timely and accurate 3D modelling and mapping of small to medium sized areas. Although the importance and applications of large format aerial overlaps cameras and photographs in Digital Surface Model (DSM) production and LIDAR data is well documented in literature, this is not the case for UAV photography. Additionally, the main disadvantage of photogrammetry is the inability to map the dead ground (terrain), when we deal with areas that include vegetation. This paper assesses the use of nearinfrared imagery captured by small UAV platforms to automatically remove vegetation from Digital Surface Models (DSMs) and obtain a Digital Terrain Model (DTM). Two areas were tested, based on the availability of ground reference points, both under trees and among vegetation, as well as on terrain. In addition, RGB and near-infrared UAV photography was captured and processed using Structure from Motion (SfM) and Multi View Stereo (MVS) algorithms to generate DSMs and corresponding colour and NIR orthoimages with 0.2m and 0.25m as pixel size respectively for the two test sites. Moreover, orthophotos were used to eliminate the vegetation from the DSMs using NDVI index, thresholding and masking. Following that, different interpolation algorithms, according to the test sites, were applied to fill in the gaps and created DTMs. Finally, a statistic analysis was made using reference terrain points captured on field, both on dead ground and under vegetation to evaluate the accuracy of the whole process and assess the overall accuracy of the derived DTMs in contrast with the DSMs. [ABSTRACT FROM AUTHOR]

The term Unmanned Aerial Vehicle (UAV) is often directly associated with the armed forces due to their widely-criticized use of such vehicles on the modern battlefield. However, with the advancement of UAV technology, the acquisition and operational cost of small civilian UAV have reduced while their functionalities have increased. Therefore, a wide variety of new civilian applications have emerged. Mapping industry has been benefited as affordable UAV can partially replace traditional platforms, such as helicopters and small aircrafts, for low altitude photography acquisition. Although relatively new to the industry, the use of UAV is rapidly commercialized and they are expected to have a sizeable impact on the mapping industry in the coming years. The aim of this work was to test the use of a low-cost UAV for orthophoto production and Digital Surface Model (DSM) creation, to be used for the design of a new 23km high voltage line of Electricity Authority of Cyprus. [ABSTRACT FROM AUTHOR]

A fuzzy model was designed to characterize the quality of mandarin irrigation water. The model consisted of individual cascade submodels. This procedure simplifies the process, and on the other hand allows us to study the effect of individual variables in the final decision. Precisely, the effect of three irrigation water resources (Irrigators association water (IW), Reclaimed Water, and Transferred Water) were studied on the development of mandarin’s tree crop. The application of the model showed that the IW irrigation gives the best results. [ABSTRACT FROM PUBLISHER]

Photogrammetry is a valid alternative solution to linear variable differential transformer (LVDT) measurements in structural testing in laboratory conditions. Although the use of LVDTs boasts a high degree of accuracy, on the other hand it is limiting as it offers measurements between two points and it thus might be unable to capture localized deformations and strains over a bigger area of a structural specimen. In this aspect photogrammetry seems to offer certain advantages. Commercial solutions provide limited testing envelopes, while on the other hand, the wide range on new materials need more versatile techniques. Based on the need to develop an in-house photogrammetric toolbox to support several structural and material experiments in the department Advanced Pore Morphology (APM) aluminium foam specimens developed at Fraunhofer IFAM in Germany and cured at CUT, were tested under monotonic compressive load. Data acquisition, analysis and results, along with lessons learnt from the process are presented in this work. [ABSTRACT FROM AUTHOR]